True knowledge to nature is the true presentation of causality. We can not
prove if or why there is such a causality existing, but we can do better if we
assume there is by linking up phenomena with causalities, giving reasons for
them and making predictions with them, and we do achieve some command of our own
fate working in such a way, less rely on god for all our needs.

With true knowledge, there is far more amount of false knowledge, that is not true to
nature. It is the
byproduct of testing links, we should be careful not to suffer from the
byproducts.

So knowledge by nature is subjective and should be open to examination to
keep it in compliance with nature behavior.

Is memory or a sight or experiencing a piece of knowledge? They are
data or raw materials rather than knowledge, we build knowledge with them.